Effect of EPs7630 (Umckaloabo®) on the adherence of Streptococcus pyogenes to human epithelial cells

Abstract number: 903_r2124

Lallemand C.

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Introduction:

EPs7630 (Umckaloabo®,ISO-Pharmaceuticals, Germany) is an extract of the root of the South African geranium Pelargonium sidoides. The phytotherapeutic remedy has been successfully used for the treatment of upper-respiratory tract infections (Phytomedicine 2003; 10, 717).

Study objective:

To investigate the biological effects of EPs7630 in the pathogenesis of upper-respiratory tract infection.

Material and methods:

Using a flow cytometric technique, we assessed the influence of EPs7630 on streptococcal adherence (i) to the human HEp-2 cell line (90% viable) and (ii) to human buccal epithelial cells (BEC; 90% dead), sloughed off from the oral mucosa. Streptococcus pyogenes (DSM 2071) was stained with Calcein-AM which is retained by viable bacteria. Adherence was determined after incubating bacteria and epithelial cells for 120 min. EPs7630 was applied in five concentrations, 30, 10, 3.0, 1.0 and 0.3 mg/mL. Alternatively, either streptococci or epithelial cells were preincubated with EPs7630 and washed before further incubation. The readout was the percentage of epithelial cells with adhering fluorescent bacteria.

Results:

Streptococcal adherence to HEp-2 cells decreased significantly with rising concentrations of EPs7630: for 30, 10 and 3.0 mg/mL adherence was reduced by factors 0.54, 0. 6 and 0.7, respectively. In contrast, streptococcal adherence to BEC increased significantly under treatment with EPs7630: for 30 mg/mL by factor 7, for 3.0 mg/mL by factor 2.9, and for 1.0 mg/mL by factor 1.7. Preincubation of bacteria with EPs7630 showed similar results, whereas preincubation of epithelial cells had no effect.

Conclusions:

The decrease in bacterial adherence to viable HEp-2 cells and the increase in bacterial adherence to dead BEC under the influence of EPs7630 could be an important mechanism in preventing and mitigating upper respiratory tract infections.